In a tire 2, load support layers 20 extend, in portions inward of a carcass 10, from portions inward of beads 8, respectively, in the axial direction to portions inward of a tread in the radial direction. When a reference point P represents a point, on an outer surface of the tire 2, which is distant from a bead base line by 25 mm in the radial direction, a distance D1, at the reference point P, from the outer surface of the tire 2 to an outer side surface of a main portion 36 of a carcass ply 34 is greater than or equal to 3 mm and not greater than 10 mm.

A run-flat tire includes a side reinforcing rubber layer, a first bead filler on an inner side of a carcass turned-up portion in a width direction, and a second bead filler on an outer side of the carcass turned-up portion in the width direction. A first bead filler height is 30% or less of a tire cross-sectional height SH. A second bead filler height is 50% or greater of the height SH. A cross-sectional area of the second bead filler is from 150% to 400% of a cross-sectional area of the first bead filler. A relationship (0.16×SH×LI−1100)≤S.sub.ALL≤(0.16×SH×LI−800) is satisfied, where S.sub.ALL represents a sum of cross-sectional areas of the side reinforcing rubber layer and the first and second bead fillers, and LI represents a load index.

A run-flat tire includes reinforcing rubber in a sidewall, first bead filler rubber disposed toward the inside of a folded back portion of a carcass layer in a lateral direction, and second bead filler rubber disposed toward the outside of the folded back portion in the lateral direction. The reinforcing rubber has a thickness from a rim base line to a position within 38% to 68% of a tire cross-sectional height being from 90% to 100% of a maximum thickness of the reinforcing rubber. In a range from a position of a rim check line to a position being 38% of the tire cross-sectional height from the rim base line, a total thickness of the reinforcing rubber, the first bead filler rubber, and the second bead filler rubber is from 100% to 140% of the maximum thickness of the reinforcing rubber.

A run-flat tire includes: sipes formed in blocks; a belt reinforcing layer on an outer side in a radial direction of a belt layer; and a side reinforcing rubber in sidewall portions, wherein a density of the sipes in a center block is from 0.10 cords/mm or greater to 0.30 cords/mm or smaller, the belt reinforcing layer includes a center reinforcing portion in which more center reinforcing portions are stacked at a center region than at positions other than the center region, a width Wc of the center reinforcing portion is within 0.5 Gr≤Wc≤2.5 Gr with respect to a thickness Gr of the side reinforcing rubber at the tire maximum width position, and an average width of the width Wc of the center reinforcing portion is from 50% or greater to 90% or smaller of a width of the center block.

A pneumatic tire is provided. A bead filler is disposed on an outer circumferential side of each bead core in bead portions, a side reinforcing layer having a crescent-shaped cross-section is disposed on an inner side in a tire width direction of a carcass layer in a sidewall portion, and as physical properties of a rubber that constitutes the side reinforcing layer and a rubber that constitutes the bead filler, a modulus at 100% elongation is in a range from 8.4 MPa to 10.2 MPa, a tan δ at 60° C. is in a range from 0.04 to 0.08, and JIS hardness at 20° C. is in the range from 75 to 79.

A run-flat tire includes side reinforcing rubber between a carcass layer and an innerliner layer in sidewall portions, first bead filler rubber arranged inside folded back portions of the carcass layer, and second bead filler rubber arranged outward of the folded back portions of the carcass layer in a lateral direction and along the carcass layer. In a meridian cross-section, a radial-direction height of the first bead filler rubber is 15% or greater and 40% or less of a cross-sectional height, a radial-direction height of the second bead filler rubber is 35% or greater and 55% or less of the cross-sectional height, a linear distance from a radial-direction outer end to a radial-direction inner end of the second bead filler rubber is 20% or greater and 45% or less of the cross-sectional height, and the second bead filler rubber has a larger cross-sectional area than the first bead filler rubber.

A run-flat tire has a belt-end reinforcing layer provided between the tread portion and a width outside end of the belt layer, and formed of a resin material. The belt-end reinforcing layer is annular along a tire circumferential direction, has a predetermined width along the tire width direction, and is provided in the tire width direction so as to cover a radial outside end of a side reinforcing rubber and a width outside end of the belt layer.

A run-flat tire includes: sipes formed in blocks; a belt reinforcing layer on an outer side in a radial direction of a belt layer; and a side reinforcing rubber in sidewall portions, wherein a density of the sipes in a center block is from 0.10 cords/mm or greater to 0.30 cords/mm or smaller, the belt reinforcing layer includes a center reinforcing portion in which more center reinforcing portions are stacked at a center region than at positions other than the center region, a width Wc of the center reinforcing portion is within 0.5 Gr≤Wc≤2.5 Gr with respect to a thickness Gr of the side reinforcing rubber at the tire maximum width position, and an average width of the width Wc of the center reinforcing portion is from 50% or greater to 90% or smaller of a width of the center block.

A pneumatic tire has a designated vehicle inner/outer side orientation for when mounted on a vehicle, and includes: a reinforcing rubber layer disposed in sidewall portions on sides in a tire lateral direction, the reinforcing rubber layer having a crescent shaped meridian cross-section; wherein a radius of curvature with an arc joining intersections of straight lines and a tire external contour, and a radius of curvature with an arc joining intersections of the straight lines and a carcass layer have a relationship such that, on the vehicle outer side, a radius of curvature of the carcass layer is large with respect to a radius of curvature of the tire external contour, and on the vehicle inner side, a radius of curvature of the carcass layer is small with respect to a radius of curvature of the tire external contour.

A run-flat tire includes reinforcing rubber in a sidewall, first bead filler rubber disposed toward the inside of a folded back portion of a carcass layer in a lateral direction, and second bead filler rubber disposed toward the outside of the folded back portion in the lateral direction. The reinforcing rubber has a thickness from a rim base line to a position within 38% to 68% of a tire cross-sectional height being from 90% to 100% of a maximum thickness of the reinforcing rubber. In a range from a position of a rim check line to a position being 38% of the tire cross-sectional height from the rim base line, a total thickness of the reinforcing rubber, the first bead filler rubber, and the second bead filler rubber is from 100% to 140% of the maximum thickness of the reinforcing rubber.